immatch: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/immatch - from package: wcstools

You may install the required package with command apt-get install {package}

Error in other languages:
immatch: bevel nie gevind nie
immatch: comandă negăsită
immatch: comando não encontrado
immatch: commande introuvable
immatch: command not found
immatch: käsku ei ole
immatch: không tìm thấy lệnh
immatch: komanda nerasta
immatch: Kommando nicht gefunden.
immatch: kommandot finns inte
immatch: komut yok
immatch: nie znaleziono polecenia
immatch: níor aimsíodh an t-ordú
immatch: no se encontró la orden
immatch: no s'ha trobat l'ordre
immatch: opdracht niet gevonden
immatch: parancs nem található
immatch: perintah tidak ditemukan
immatch: príkaz nenájdený
immatch: příkaz nenalezen
immatch: команда не найдена
immatch: командата не е открита
immatch: 命令找不到
immatch: コマンドが見つかりません